“My first foreign trip as President of the United States will be to Saudi Arabia, then Israel, and then to a place that my cardinals love very much – Rome,” he said during his speech, prior to which Cardinal Donald Wuerl, Archbishop of Washington, had delivered a prayer address.

The Vatican confirmed that the meeting would take place at 8:30 Wednesday morning (Rome time) in the Apostolic Palace. The day, as well as the timing, is being called unusual, given the early hour and the fact that the meeting had to be squeezed in before the Pope’s weekly general audience.

The meeting will be interesting, to say the least, given the leaders opposing views on issues such as climate change and immigration.

President Trump has promised to protect America’s borders, even if that means making a wall. Pope Francis, however, has called the immigration crisis the “greatest tragedy” since World War II.

President Trump is skeptical of so-called “man-made” climate change and has signed an executive order undoing much of the Obama administration’s environmental legislation. Pope Francis, however, has written an entire encyclical about climate change, calling it real and mainly “a result of human activity.”

During the U.S. election campaign, Francis called then-candidate Trump's plan to protect America by building a wall on Mexico’s border "not Christian.”

“A person who only thinks about building walls, wherever they may be, and not building bridges, is not Christian,” the pope said.

But Trump retorted in a statement on his campaign website: "No leader, especially a religious leader, should have the right to question another man's religion or faith."

Then, in a speech delivered at the Vatican three days prior to the U.S. election, Francis urged Christians to not give into the politics of “fear” by building “physical and social walls.”

Interestingly, the day Trump was being sworn in as the 45th President of the United States in January, Francis warned against the rise of populist leaders like Adolf Hitler, stating that “Hitler didn't steal power, his people voted for him, and then he destroyed his people.”

Last month Cardinal Peter Turkson, Francis’ point man for the environment, immigration, and development, urged Trump to listen to "dissenting voices" and reconsider his position on climate change.

The meeting will likely be watched closely by many, especially given Trump’s penchant for speaking his mind and Francis’ habit of making off-the-cuff comments that are often controversial.